Electromagnetic Waves - Result Question 19
19. The frequency of electromagnetic wave, which is best suited to observe a particle of radius $3 \times 10^{-4} cm$ is of the order of
(a) $10^{15}$
(b) $10^{14}$
(c) $10^{13}$
(d) $10^{12}$
[1991]
Topic 2: Electromagnetic Spectrum
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Answer:
Correct Answer: 19. (b)
Solution:
- (b) Size of particle $=\lambda=\frac{c}{v}$
$3 \times 10^{-6}=\frac{3 \times 10^{8}}{v}$
$v=10^{14} Hz$
When frequency is higher than this, wavelength is still smaller. Resolution becomes better.
